Crab traps are widely employed in coastal waters. One of the most prevalent floats is a cylindrical body of styrofoam through which a rope-receiving float tube extends. The tube is flared outward at inner and outer dimensions to hold the tube in the styrofoam ball and to allow rope contact around a smooth rounded surface rather than at an edge. Traditionally, a crab trap rope is attached to a crab trap. A knot is formed at a position which will be below the float and the free end of the rope is passed through the tube. Another knot is formed at the top of the tube, securing the rope to the float.
Crabs are harvested by moving an open top work boat at about five knots, and engaging the rope beneath the water line with teeth on a rack of a frame.
The rack and knot or the rack and float absorb the reactive force as the rope is stretched taut and the crab trap is lifted from the bottom. The rope is then grabbed with a hook or by hand and hauling the rope in releases the tension on the float, allowing the float to bob through the frame. The crab trap is hauled up to the boat and is emptied into the boat, and then is released back into the water, all while the boat is under way, headed toward the next float. By the time the trap is emptied, the next float may already be caught by the underwater rack.
To prevent the top knot from pulling through the float, it is customary to cut a short length of polyvinyl chloride pipe and to drill holes diametrically through the holes in the pipe and pass the rope through the pipe before tying the top knots. That increases longevity of the float and helps to prevent the rope from being pulled through the float, with the attendant loss of the crab trap.
The loss of the crab trap during harvesting is one of the worst problems that confronts a waterman crab harvester.
The bottom knot below the float is useful only to prevent the float from moving along the rope. If the float moves along the rope so that the float is displaced from the upper end of the rope, a jarring occurs during harvesting. That is because the rope slides through the rack, slides through the float and abruptly contacts the end of the rope, resulting in the jarring and possible loss of the crab trap.
Due to the floating and bobbing of the float, there is much pushing and pulling on the knots and the knots tend to work loose. As the rope and float are engaged by the rack during harvesting, it is not unusual for the top knot, which has been loosened by wave action or repeated harvesting, to become totally untied, allowing the float to slip off the rope and resulting in the loss of the crab trap.
A long-standing need has existed to create a better float-rope connection for crab harvesting cages.
The prior method of securing a float to a crab trap required several steps:
Step One: Purchase a 20 ft. length of PVC pipe. PA0 Step Two: Cut the PVC pipe into approximately 3 inch lengths. PA0 Step Three: Drill 1/4 inch diametrical holes in the center of the 3 inch piece. PA0 Step Four: Thread a 1/4 inch rope through the holes in the 3 inch piece of PVC pipe. PA0 Step Five: Tie a double knot above the 3 inch piece of PVC pipe to prevent its slipping out. PA0 Step Six: Thread the 1/4 inch rope (15 ft. to 18 ft. long, depending on depth of water) through the float. PA0 Step Seven: Tie another knot close against the bottom of the float to limit any free travel of the float between the knot and the PVC pipe piece. PA0 Step Eight: Secure the loose end of the 1/4 inch rope to the crab cage. PA0 Step One: Thread a 1/4 inch rope through the present stop and a tie knot above the stop. PA0 Step Two: Thread the loose end of a 1/4 inch rope through the float until the new stop touches the top of the float, automatically aligning itself. PA0 Step Three: Jerk firmly on the 1/4 inch rope below the float, thereby inserting the new stop into the top of the float. PA0 Step Four: Secure the 1/4 rope to the cage trap.
Each piece of 3 inch long PVC is cut by hand of power saw. The holes drilled in the center of each 3 inch piece are often distorted because of the heat generated by the drill bit. Threading the rope through the holes is difficult because of the distorted holes. Then, the knot under the float is tied to prevent free travel of the float along the rope caused by the current bobbing the float up and down. That process is used to prevent the loss of crab traps when only a knot is used in the top of the float. Also, the bobbing action frequently loosens the knot below the float, thereby allowing slack between the float and the 3 inch piece of PVC pipe on top. When this occurs, the jarring brought about by retrieving the cage causes the knot to untie, and the crab cage is lost.
In the retrieval of a crab cage, teeth on a rack are below a waterline to enable retrieving of the float which is attached to the crab cage.
With the boat traveling at approximately 5 knots, the rack teeth trap the float, latching it, and retrieve the crab trap from the bottom of the water, surfacing it for emptying the cage of its contents. When the cage is full, making it heavier, the jarring action upon latching the float is significantly increased, especially if there is any free travel of the float on the rope.
A need exists for an improved rope-crab trap float attachment.